The first heads that were legal replacements for the 65's were the "replacement heads" aka "twin plug heads" aka "Ross Foundry heads" aka "433 heads". I assume the heads made in the late 90's were also legal. They let people run all kinds of stuff in S/S now.

Last edited by rickseeman; 11/16/23 01:11 PM.
2011 Drag Pak Challenger